问题
I'm using Azure function apps with Python. I have two dozen function apps that all use a Postgres DB and Custom Vision. All function apps are setup as HttpTriggers. Right now, when a function is triggered, a new database handler (or custom vision handler) object is created, used and terminated when the function app call is done.
It seems to be very counterproductive to instantiate a new objects on every single request that comes in. Is there a way to instantiate shared objects once and then pass them to a function when they are called?
回答1:
In general, Azure Functions are intended to be stateless and not share objects from one invocation to the next. However, there are some exceptions.
Sharing Connection Objects
Azure Docs recommend the Improper Instantiation Pattern for sharing of connection objects that are intended in an application to be opened once and used again and again.
There are some things to keep in mind for this to work for you, mainly:
The key element of this antipattern is repeatedly creating and destroying instances of a shareable object. If a class is not shareable (not thread-safe), then this antipattern does not apply.
They have some walkthroughs there that will probably help you. Since your question is fairly generic, the best I can do is recommend you read through it and see if that will help you.
Durable Functions
The alternative is to consider the Durable Functions instead of the standard. They are intended to be able to pass objects between functions making them not quite stateless.
Durable Functions is an advanced extension for Azure Functions that isn't appropriate for all applications. This article assumes that you have a strong familiarity with concepts in Azure Functions and the challenges involved in serverless application development.
来源：https://stackoverflow.com/questions/55913119/azure-function-apps-with-python-one-time-initialization